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. Author manuscript; available in PMC: 2015 Aug 1.
Published in final edited form as: Med Care. 2014 Aug;52(8):695–703. doi: 10.1097/MLR.0000000000000159

Table 2.

Estimated Impact of Part D on Use of Lipid Lowering Medications among Dual Enrollees by State Drug Cap Statusa

Strict Drug Cap States
Intercept Baseline Trend Part D Trend Change Post Part D
Estimate (95% CI) p-valueb Estimate (95% CI) p-value Estimate (95% CI) p-value Estimate (95% CI) p-value
 Non-Elderly
  Any 0.19 (0.17, 0.20) <0.001 0.001 (0.0001, 0.002) 0.029 0.07 (0.05, 0.09) <0.001 0.002 (0.001 (0.003) 0.002
  SMD c 0.32 (0.28, 0.35) <0.001 0.002 (−0.001, 0.004) 0.202 0.09 (0.03, 0.14) 0.002 0.002 (−0.001, 0.01) 0.192
 Elderly
  Any 0.20 (0.19, 0.22) <0.001 0.001 (0.00004, 0.002) 0.042 0.08 (0.05, 0.10) <0.001 0.002 (0.0001, 0.003) 0.034
  SMD 0.32 (0.29, 0.35) <0.001 0.002 (0.0001, 0.004) 0.036 0.08 (0.03, 0.12) 0.002 −0.0004 (−0.004, 0.003) 0.819
No Drug Cap States
 Non-Elderly
  Any 0.35 (0.35, 0.36) <0.001 0.005 (0.004, 0.005) <0.001 −0.001 (−0.01, 0.01) 0.749 −0.004 (−0.005, −0.003) <0.001
  SMD 0.44 (0.43, 0.46) <0.001 0.01 (0.01, 0.01) <0.001 −0.01 (−0.03, 0.005) 0.144 −0.004 (−0.01, −0.003) <0.001
 Elderly
  Any 0.42 (0.41, 0.43) <0.001 0.004 (0.003, 0.004) <0.001 −0.01 (−0.03, 0.01) 0.205 −0.004 (−0.005, −0.002) <0.001
  SMD 0.48 (0.47, 0.50) <0.001 0.01 (0.01, 0.01) <0.001 0.002 (−0.02, 0.03) 0.842 −0.01 (−0.01, −0.004) <0.001
a

State Medicaid program limited monthly drug coverage to five or fewer total prescriptions or to three or fewer brand name drugs during the 24-month baseline period, 2004–2005. The 32 no-cap states were: AK, CO, CT, DC, DE, FL, HI, IA, ID, IN, MA, MD, MI, MN, MO, MT, ND, NE, NH, NJ, NM, NV, OR, RI, SD, UT, VA, VT, WA, WI, WV, WY. The 4 strict cap states were: AR, MS, OK, TX. The following 11 states had less restrictive caps: AL, CA, GA, IL, KS, KY, ME, NC, NY, PA, SC. Three states were excluded from the study due to data anomalies: AZ, LA, OH. We also excluded one state due to the introduction of a drug cap during the baseline period: TN.

b

p value < 0.006 was considered significant

c

Standardized monthly dose = median number of milligrams dispensed per month across person-months with any drug use